1. Field of the Invention
The present invention relates to a fingerprint authenticating system, a fingerprint authenticating method and a fingerprint authenticating program. More particularly, the present invention relates to a technique for using a small fingerprint sensor and carrying out a fingerprint authentication.
2. Description of the Related Art
In recent years, personal information has been registered in an information processor, such as PHS (Personal Handy-phone System), PDA (Personal Data Assistant) and a personal computer, in many cases. On the other hand, there is a problem that the personal information registered in such an information processor is illegally used by a different person. For example, in association with the miniaturization of the information processor, an opportunity that it is carried is increased to thereby bring about misplacement and loss and the like. The occurrence of such situations brings about the leakage of the personal information registered in the information processor. Thus, it is desired to develop an authenticating system having excellent convenience that can be installed in a small apparatus.
As one of such authenticating systems, a fingerprint authenticating system for using a fingerprint and carrying out an authentication is known. As one of fingerprint sensors used in this fingerprint authenticating system, a flat fingerprint sensor is known. This flat fingerprint sensor includes a reading unit having a scale corresponding to a size of a finger so that the substantially entire portion of a fingerprint can be read at one scanning operation. Thus, the flat fingerprint sensor has a problem that since its outer shape is large, the yield of a manufacture is poor and becomes thereby expensive. Hence, it is difficult to install in a small apparatus and a cheap apparatus such as a portable telephone.
As a method of solving such a problem, Japanese Laid Open Patent Application (JP-A-Heisei 10-91769) discloses a fingerprint reading system that uses a sweep type of a fingerprint sensor. In this fingerprint reading system, a user slides his or her finger while it is in contact with the fingerprint sensor when it is read. The fingerprint sensor divides the fingerprint of this slid finger into rectangular strips and reads them. A fingerprint picture obtained by this reading operation is re-configurationally processed by software. Consequently, a fingerprint picture for the entire finger is generated and used for the authentication According to this sweep type of the fingerprint sensor, the length of the sensor in the slid direction can be shortened to thereby design the fingerprint sensor at a small scale and a cheap price.
Japanese Laid Open Patent Application (JP-A 2001-155137) discloses a potable electric apparatus of a fingerprint reading system. This apparatus uses the sensor whose shape of the reading portion is like a T character.
However, the fingerprint reading system that uses the conventional sweep type fingerprint sensor as mentioned above has the following problems. Thus, the fingerprint sensor is not installed in the small apparatus and the cheap apparatus, for example, such as a portable telephone and the like. That is, this fingerprint reading system requires the operation for contacting the finger with the fingerprint sensor and sliding it. This system is not preferred since the operation compels the user to carry out a new work. Also, this system has a problem that the contaminant such as sebum and dirt of the finger is deposited around the fingerprint sensor. Moreover, this fingerprint reading system needs the re-configuration of the picture read by the fingerprint sensor. Hence, this system requires a long time for the authentication. In order to avoid this problem, a processor having a high performance needs to be installed in an apparatus.